On Fri, Nov 27, 2020 at 05:35:28PM +0100, Daniel Vetter wrote:
> Purely conjecture, but I think the original locking inversion with the
> legacy page flip code between flipping and ttm's bo move function
> shoudn't exist anymore with atomic: With atomic the bo pinning and
> actual modeset commit is completely separated in the code patsh.
>
> This annotation was originally added in
>
> commit 060810d7abaabcab282e062c595871d661561400
> Author: Ben Skeggs <bskeggs@xxxxxxxxxx>
> Date: Mon Jul 8 14:15:51 2013 +1000
>
> drm/nouveau: fix locking issues in page flipping paths
>
> due to
>
> commit b580c9e2b7ba5030a795aa2fb73b796523d65a78
> Author: Maarten Lankhorst <m.b.lankhorst@xxxxxxxxx>
> Date: Thu Jun 27 13:48:18 2013 +0200
>
> drm/nouveau: make flipping lockdep safe
>
> Acked-by: Ben Skeggs <bskeggs@xxxxxxxxxx>
> Reviewed-by: Maarten Lankhorst <maarten.lankhorst@xxxxxxxxxxxxxxx>
> Signed-off-by: Daniel Vetter <daniel.vetter@xxxxxxxxx>
> Cc: Maarten Lankhorst <m.b.lankhorst@xxxxxxxxx>
> Cc: Ben Skeggs <bskeggs@xxxxxxxxxx>
> Cc: Dave Airlie <airlied@xxxxxxxxx>
> Cc: nouveau@xxxxxxxxxxxxxxxxxxxxx
I stuffed this one into drm-misc-next now.
-Daniel
> ---
> drivers/gpu/drm/nouveau/nouveau_bo.c | 5 ++++-
> 1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/nouveau/nouveau_bo.c b/drivers/gpu/drm/nouveau/nouveau_bo.c
> index 1386b0fc1640..43069dd8b027 100644
> --- a/drivers/gpu/drm/nouveau/nouveau_bo.c
> +++ b/drivers/gpu/drm/nouveau/nouveau_bo.c
> @@ -774,7 +774,10 @@ nouveau_bo_move_m2mf(struct ttm_buffer_object *bo, int evict,
> return ret;
> }
>
> - mutex_lock_nested(&cli->mutex, SINGLE_DEPTH_NESTING);
> + if (drm_drv_uses_atomic_modeset(drm->dev))
> + mutex_lock(&cli->mutex);
> + else
> + mutex_lock_nested(&cli->mutex, SINGLE_DEPTH_NESTING);
> ret = nouveau_fence_sync(nouveau_bo(bo), chan, true, ctx->interruptible);
> if (ret == 0) {
> ret = drm->ttm.move(chan, bo, &bo->mem, new_reg);
> --
> 2.29.2
>
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
_______________________________________________
dri-devel mailing list
dri-devel@xxxxxxxxxxxxxxxxxxxxx
https://lists.freedesktop.org/mailman/listinfo/dri-devel
